Oil filters are well known for use with internal combustion engines for filtering the oil used to lubricate the engine. Most filters are similar in structure and include a cylindrical filter body attached at one end to a filter plate. The filter plate can be screwed onto the engine to couple the filter to the engine. A suitable porous filter media is contained inside the filter body for removing contaminants as the oil passes through the filter. The filter plate includes a plurality of circumferentially spaced holes arrayed in a circle for allowing the oil to enter or leave the filter body.
A filter wrench comprising an adjustable band is known for removing oil filters when changing oil or the like. This band simply comprises a strap which encircles the filter body and is tightened around the filter body. Then, when the strap or band is turned by means of an attached handle, the filter body is rotated to unscrew the filter from the engine.
Unfortunately, oil filters often become stuck on the engine. The use of the known adjustable band filter wrench often crushes the filter body if the filter is stuck. Then, the filter body has to be sawed or cut off, and the filter plate removed separately using a hammer and screwdriver to slowly rotate the filter plate off. Needless to say, this is a time consuming and frustrating process.
Another known prior art tool is designed to help remove a stuck oil filter plate once the filter body is cut away. This tool has a rectangular base plate with a cylindrical socket projecting upwardly therefrom and two pins projecting downwardly therefrom spaced inwardly from the sides of the base plate. The pins are received in the holes on the oil filter plate and a ratchet wrench is coupled to the socket for turning the base plate and causing the pins to remove the oil filter plate. Various sizes of the tool are provided with the pins being spaced apart different distances.
One disadvantage of the last described tool is that it is relatively expensive to manufacture. The pins have to be welded or otherwise securely attached to the base plate. A socket has to be provided and further secured to the base plate. The need for these manufacturing steps increases the cost and complexity of the tool. In addition, a different tool is required for each filter size. Since there are four common filter sizes (i.e. filters where the holes are located on circles having different diameters), four separate tools are required in a complete set. This also contributes to increased cost.
A final disadvantage of this tool is that it can't be used to remove a complete filter, but only the filter plate. Thus, the mechanic or automobile owner has to have the typical adjustable band filter wrench, or some other tool, to try and remove the filter when the filter body is still attached to the filter plate.